1.7/1.8/1.9

Is it possible to make a 1.7/1.8/1.9 hub? I know there are some servers that have 1.7/1.8 but is 1.7/1.8/1.9 possible?

If it isn't possible, is it possible to create a plugin that can identify the client version and send it to the server that has the same version?